You're talking about the specifics of this library. As you said in your original comment, that would apply to any C++ library using shared_ptr too across the AP

You're talking about the specifics of this library. As you said in your original comment, that would apply to any C++ library using shared_ptr too across the API boundary. A different non-GC language wouldn't change things, because you'd have the exact same trade off if the same decision was made. The only major difference is that Rust pushes you to Arc but C++ doesn't push you to a shared_ptr.